answers.md

Q1. Notebook

We'll start with the same notebook we ended up with in homework 1. We cleaned it a little bit and kept only the scoring part. You can find the initial notebook here.

Run this notebook for the February 2022 data.

What's the standard deviation of the predicted duration for this dataset?

• 5.28
• 10.28
• 15.28
• 20.28

Q2. Preparing the output

Like in the course videos, we want to prepare the dataframe with the output.

First, let's create an artificial ride_id column:

df['ride_id'] = f'{year:04d}/{month:02d}_' + df.index.astype('str')

Next, write the ride id and the predictions to a dataframe with results.

Save it as parquet:

df_result.to_parquet(
    output_file,
    engine='pyarrow',
    compression=None,
    index=False
)

What's the size of the output file?

• 28M
• 38M
• 48M
• 58M

Note: Make sure you use the snippet above for saving the file. It should contain only these two columns. For this question, don't change the dtypes of the columns and use pyarrow, not fastparquet.

Q3. Creating the scoring script

Now let's turn the notebook into a script.

Which command you need to execute for that?

jupyter nbconvert --to script starter.ipynb

Q4. Virtual environment

Now let's put everything into a virtual environment. We'll use pipenv for that.

Install all the required libraries. Pay attention to the Scikit-Learn version: it should be scikit-learn==1.2.2.

After installing the libraries, pipenv creates two files: Pipfile and Pipfile.lock. The Pipfile.lock file keeps the hashes of the dependencies we use for the virtual env.

What's the first hash for the Scikit-Learn dependency?

pip install pipenv 

pipenv install scikit-learn==1.2.2 pandas pyarrow

Q5. Parametrize the script

Let's now make the script configurable via CLI. We'll create two parameters: year and month.

Run the script for March 2022.

What's the mean predicted duration?

• 7.76
• 12.76
• 17.76
• 22.76

Hint: just add a print statement to your script.

Q6. Docker container

Finally, we'll package the script in the docker container. For that, you'll need to use a base image that we prepared.

This is how it looks like:

FROM python:3.10.0-slim

WORKDIR /app
COPY [ "model2.bin", "model.bin" ]

(see homework/Dockerfile)

We pushed it to svizor/zoomcamp-model:mlops-3.10.0-slim, which you should use as your base image.

That is, this is how your Dockerfile should start:

FROM svizor/zoomcamp-model:mlops-3.10.0-slim

# do stuff here

This image already has a pickle file with a dictionary vectorizer and a model. You will need to use them.

Important: don't copy the model to the docker image. You will need to use the pickle file already in the image.

Now run the script with docker. What's the mean predicted duration for April 2022?

• 7.92
• 12.83
• 17.92
• 22.83

Bonus: upload the result to the cloud (Not graded)

Just printing the mean duration inside the docker image doesn't seem very practical. Typically, after creating the output file, we upload it to the cloud storage.

Modify your code to upload the parquet file to S3/GCS/etc.